A greatcoat, (Russian: Шинель, translit. Shinel) also known as a watchcoat, is a large overcoat typically made of wool designed for warmth and protection against the weather. Its collar and cuffs can be turned out to protect the face and hands from cold and rain, and the short cape around the shoulders provides extra warmth and repels rainwater (if made of a waterproof material). It was popular in the 19th century as a military uniform and casual wear for the wealthy, and is still issued for inclement weather by many armed forces around the world. During the 17th and 18th centuries and the Industrial Revolution, greatcoats became available for all social classes.

The coat generally hangs down below the knees and the cape is kept short, normally just above or below the elbows. It also sports deep pockets for keeping letters and food dry. It is typically coloured grey, though other colours may be used (e.g. black, brown, navy blue). One type of greatcoat is the Petersham (after Petersham in Surrey).